Cash and Investments in Marketable Securities - Portfolio of Cash and Investments in Marketable Securities (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross Unrealized Losses		$ (700)
Cash	$ 18,726	1,250
Total cash and investments in marketable securities	628,244	798,783
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	561,402
Gross Unrealized Gains	0
Gross Unrealized Losses	(3,742)
Fair Value	557,660	762,625
Level 2 | Corporate notes and bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	141,416
Gross Unrealized Gains	0
Gross Unrealized Losses	(1,505)
Fair Value	139,911	278,121
Level 2 | Corporate commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	415,106
Gross Unrealized Gains	0
Gross Unrealized Losses	(2,232)
Fair Value	412,874	478,629
Level 2 | Obligations of U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	4,880
Gross Unrealized Gains	0
Gross Unrealized Losses	(5)
Fair Value	4,875	5,875
Level 2 | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	9,516	10,940
Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	$ 42,342	$ 23,968